ValueConstraint Property

Gets or sets the constraints for editor input. Default value is null.
Public Property ValueConstraint As ValueConstraint
public ValueConstraint ValueConstraint {get; set;}

Note that the default value of this property is null. You must set the property to an instance of ValueConstraint object.

ValueConstraint is used to limit what the user can input into the editor. More accurately, the editor will consider user input invalid if it doesn't satisfy one or more criteria specified by the ValueConstraint. The IsValueValid property can be used to find out if editor considers current value valid.

When an invalid value is entered into the editor, there are behavioral implications based on various settings. For example, by default the editor doesn't exit edit mode when the current input is invalid. The action taken by the editor can be controlled using the InvalidValueBehavior property.

The following code snippet sets the ValueConstraint on a text editor. It sets the MinLength and MaxLength properties of the value constraint. This will ensure that the length of what user enters into the editor is between 2 and 4 characters. If the value entered does not satisfy all the constraints of the value constraint object then the editor will display an error message when the user attempts to leave the editor. The action taken by the editor can be controlled using the InvalidValueBehavior property of the editor.

<!--This editor will make sure that the text entered is between 2 and 4 characters long-->
<igEditors:XamTextEditor x:Name="textEditor3" InvalidValueBehavior="DisplayErrorMessage" >
<igEditors:ValueConstraint MinLength="2" MaxLength="4" />

Target Platforms: Windows 10, Windows 8.1, Windows 8, Windows 7, Windows Server 2012, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

See Also